Electrochemical analysis of poly(3,4-ethylenedioxythiophene) (PEDOT)-modified electrodes in various aqueous/nonaqueous electrolyte solutions and implications for microfluidics using redox-magnetohydrodynamic.

by Magness, Megan; Fritsch, Ingrid

Microfluidics allows for the miniaturization of lab. equipment with goals toward low cost, fast results, high throughput and minimal prodn. time, creating the push toward small scale innovation. MHDs (MHD) offers a means to finely control local fluid flow in microfluidics devices and is portable. MHD uses the magnetic portion of the Lorentz body force, FB, resulting from an ionic current (j, normalized to area), produced between a pair of electrodes by applying an electronic current, and a magnetic flux (B) perpendicular to j. Fluid is propelled in the direction and proportional to the magnitude of FB; the fluid can also easily reverse direction by changing the direction of j. MHD eliminates the demand for moving mech. parts necessary in traditional pumping methods and introduces the possibility of pumping with or without channels. Poly(3,4-ethylenedioxythiophene) is a conducting polymer that can be electropolymd. onto an electrode, maximizing ionic c.d. and coulombic capacity. This work explores the behavior of PEDOT-modified band electrodes in electrolyte solns. having a range of different vol. ratios of water-to-org. solvent. Discussion will involve how that behavior translates to performance for R-MHD microfluidics in those fluids. Fluid speeds and flow profiles will be reported. These studies are relevant for applications of R-MHD where non-aq. conditions are of interest, such as in reverse-phase chem. sepns. with different mobile phases.